1. Field of the Invention
The present invention relates to an optical code division multiple access (CDMA) encoder and/or decoder, and more particularly, to an acousto-optic filter used for an optical CDMA decoder and/or encoder and an optical CDMA system using the same.
2. Description of the Related Art
Conventional wavelength domain optical CDMA encoders and/or decoders mainly include fiber Bragg gratings (FBGs) or general diffraction gratings.
Optical CDMA encoders and/or decoders using general diffraction gratings divide light according to a wavelength using the general diffraction gratings, transmit or reflect optical signals having specific wavelengths, and sum the divided optical signals using the general diffraction gratings so as to perform encoding and/or decoding. Thus, the optical CDMA encoders and/or decoders have large volumes and complicated structures.
Optical CDMA encoders and/or decoders using FBGs arrange reflected wavelengths of optical filters including the FBGs using arbitrary signs so as to perform encoding and/or decoding. Thus, the optical CDMA encoders and/or decoders include several FBGs.